We have recently identified a novel cell surface glycoprotein (HBHA) on mycobacteria which mediates adherence of mycobacteria to certain host cells. TB patients produce significant antibodies to HBHA compared with normal controls. We are developing an intranasal challenge model in mice to investigate the role of HBHA in protective immunity. Initial results suggest that monoclonal antibodies against HBHA decrease the colonization of the trachea and lungs by pathogenic mycobacteria as well as dissemination of bacteria to the spleen. The role of HBHA in passive and active immunication against animal models of TB will be further investigated.